US4268088A - Shortwall mining of trona - Google Patents
Shortwall mining of trona Download PDFInfo
- Publication number
- US4268088A US4268088A US06/080,271 US8027179A US4268088A US 4268088 A US4268088 A US 4268088A US 8027179 A US8027179 A US 8027179A US 4268088 A US4268088 A US 4268088A
- Authority
- US
- United States
- Prior art keywords
- trona
- mined
- entry
- mining
- trona bed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 title claims abstract description 135
- 241001625808 Trona Species 0.000 title claims abstract description 135
- 238000005065 mining Methods 0.000 title claims abstract description 58
- 238000000034 method Methods 0.000 claims abstract description 35
- 230000015572 biosynthetic process Effects 0.000 claims abstract 4
- 239000000463 material Substances 0.000 abstract description 3
- 230000000694 effects Effects 0.000 abstract description 2
- 238000005422 blasting Methods 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 238000011084 recovery Methods 0.000 description 6
- 238000011161 development Methods 0.000 description 3
- 230000018109 developmental process Effects 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- 235000015076 Shorea robusta Nutrition 0.000 description 2
- 244000166071 Shorea robusta Species 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 239000004058 oil shale Substances 0.000 description 2
- 238000004901 spalling Methods 0.000 description 2
- 230000002269 spontaneous effect Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 235000019994 cava Nutrition 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002085 persistent effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910000031 sodium sesquicarbonate Inorganic materials 0.000 description 1
- 235000018341 sodium sesquicarbonate Nutrition 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 230000033772 system development Effects 0.000 description 1
- WCTAGTRAWPDFQO-UHFFFAOYSA-K trisodium;hydrogen carbonate;carbonate Chemical compound [Na+].[Na+].[Na+].OC([O-])=O.[O-]C([O-])=O WCTAGTRAWPDFQO-UHFFFAOYSA-K 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/20—Methods of underground mining; Layouts therefor for rock salt or potash salt
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/24—Methods of underground mining; Layouts therefor for oil-bearing deposits
Definitions
- the rising economic and environmental cost of recovering natural resources has stimulated interest in utilizing methods of recovery to produce as little waste of the resources as possible without substantial increases in cost.
- mining differs from manufacturing industries in that an increased productivity must inevitably result in a shortened mine life unless the increased productivity results from an improvement in recovery techniques.
- the invention relates to an improved method of mining trona mineral, such as is found in southeastern Wyoming and similar trona deposits situated elsewhere, with increased recovery of trona over conventional methods without substantial increase in cost.
- Trona mineral or natural sodium sesquicarbonate, having the formula
- the Wyoming trona deposits are evaporites, as hereinabove described, and hence form substantially horizontal layers.
- the beds vary greatly in thickness, from about 1 foot to about 16 feet. However, the beds are persistent and extend for about 1000 square miles, thus providing reserves adequate for reasonably forseeable future needs.
- the beds are located approximately 800 feet to approximately 2000 feet below ground surface.
- a main trona bed, averaging a thickness of about 8 feet to about 11 feet is located approximately 1200 feet to approximately 1600 feet below ground surface.
- the main bed is located below substantially horizontal layers of sandstones, siltstones and mainly unconsolidated shales.
- main trona bed In particular, within about 400 feet above the main trona bed are layers of mainly weak, laminated green-grey shales and oil shale, interbedded with bands of trona from about 4 feet to about 5 feet thick. Immediately below the main trona bed lie substantially horizontal layers of somewhat plastic oil shale, also interbedded with bands of trona. Both overlying and underlying shale layers contain methane gas.
- the comparative compressive strengths, in pounds per square inch, of the main trona bed and of the overlying and underlying shale layers in average values is substantially as follows:
- both the immediately overlying and the immediately underlying layers are substantially weaker than the main trona bed.
- Recovery of the main trona bed accordingly, essentially comprises removing the only strong layer within its immediate vicinity.
- the shearer or plow is pulled back and forth across the exposed longwall trona face, and loosened trona is dropped into a conveyor.
- Self-advancing hydraulic jacks or chocks support the roof and follow the plow or shearer as it slices into the trona bed.
- the hydraulic roof supports whether chock or shield types, support the immediate roof and overlying layers. When advanced this support is removed and the weight of the overburden creates the fall necessary to remove the excess pressure at the exposed trona face, thereby providing protection from unplanned cavings.
- the hydraulic roof supports control the caved overburden, or gob, and segregates this caved material from the active working face.
- the mining can either proceed away from the main haulage road, in which case it would be termed advance longwall mining, or it can proceed towards the main haulage road, in which case it would be termed retreat longwall mining.
- trona panels of about 2,000 feet to about 4,000 feet in length and about 300 feet in width have been successfully mined.
- a waste area is left behind known as goaf or gob.
- the gob consists generally of the mined-out area in which the roof has collapsed once no longer supported by the self-advancing chocks.
- goaf a waste area
- the gob consists generally of the mined-out area in which the roof has collapsed once no longer supported by the self-advancing chocks.
- gob consists generally of the mined-out area in which the roof has collapsed once no longer supported by the self-advancing chocks.
- the plow or shearer used to mine the exposed longwall cannot be used to develop new panels. Hence, the working of the longwall face and development of new panels must be properly spaced or else expensive machinery will be idled.
- a typical longwall face is about 300 feet to 500 feet in length, and the practice has been usually to place supports approximately every three to five feet along the exposed trona face. These supports are very costly. Further, this usual length of longwall trona face is generally greater than the pressure arch of the overburden, and accordingly results in a tendency to overload the supports. Additionally, as hereinabove mentioned, the double drum shearer loader or plow cannot be used for development work, and so system development work must be properly paced or major pieces of equipment will be idled.
- the method of the present invention includes the steps of driving first and second entry ways into a trona bed to a distance of substantially equal lengths.
- the entry ways are spaced from one another a distance substantially less than the length of the respective entry ways. Further, the entry ways are spaced from one another a distance less than that of the pressure arc formed over the mined out cavity.
- the first and second entries are connected to one another by means of a passageway which defines the trona bed to be mined.
- the trona bed to be mined is of a substantially rectangular shape.
- the upper section of the connecting passage means is supported adjacent the trona panel to be mined.
- the mined strip is of a length substantially less than that of said entry means and preferably is of a length between 100 to 200 feet.
- the trona bed is thus mined removing substantially the entire layer of trona without the drawbacks of the prior art methods.
- the step of mining is conducted continuously in a single direction. More specifically, mining is conducted from the entry which serves as the intake airway in a direction toward the entry serving as the return airway. In this manner, the operator is away from the trona face which may be subject to spalling. Mining is accomplished by positioning a plurality of hydraulic support members immediately adjacent the strip of the trona bed to be mined with the support members being progressively advanced as mining advances.
- Still another object of this invention is to provide an effective and efficient method of mining trona in which the costs are below those of existig methods.
- FIG. 1 is a plan view of a mine level illustrating the application of the present invention in the extraction of a trona panel as mining progresses;
- FIGS. 2A through 2E are side elevation views, partially in cross-section, depiciting the sequential advancement of the hydraulic support member
- FIG. 3 is an enlarged plan view of the mine level illustrating the manner of mining the trona panel.
- FIG. 4 is an enlarged side elevation view, partially in cross-section, depicting the hydraulic roof support engaging the upper shale roof.
- the present invention utilizes a mining technique useful for extracting trona ore from substantialy horizontal beds of trona in which substantially parallel entries are driven into the trona bed approximately 100 feet to 200 feet apart, which entries are then connected by at least one primary passage thereby defining a trona panel to be mined.
- the roof of the primary connecting passage is supported by means of movable roof supporting structures positioned adjacent the exposed face of the trona panel to be mined.
- the roof supporting structures are advanced as the mining proceeds so that they remain essentially adjacent and parallel to the mined face as it recedes.
- the roof supporting structures are continuously advanced to incrementally effect spontaneous caving of the previously supported roof.
- trona face being mined is only about 100 feet to about 200 feet in length, less supporting structures are needed than are presently required in current longwall practice. Further, the trona face may be mined using the same equipment that was used to develop the entries and primary passage.
- FIG. 1 a mining pattern is depicted where the trona panel is formed between interconnected parallel entries.
- the mined out trona panel 10 is bounded by entries 20 and 21 while the trona panel 11 being mined is bounded by parallel entries 21 and 22.
- the remaining trona panels 12 and 13 to be mined are bounded by entries 22-23 and 23-24 respectively.
- the entries are spaced from one another a distance of approximately 100 to 200 feet which is substantially less than that of the length of the entry.
- Each of the adjacent entries are interconnected by primary passage means 25 at one end and primary passage means 26 at the other end.
- the trona bed to be mined is thus rectangular with the short wall thereof extending approximately 100 to 200 feet, a distance which is less than that of the pressure arc ultimately formed over the mined out cavity.
- roof supporting pillars 14 are likewise substantially as high as the thickness of the trona bed being mined.
- Entries 20-24, the cross-cuts and passages 25 and 26 are used for ventilation, haulage of mined trona from the active mining area and for the movement of men and equipment.
- the roof supporting structures consist of a plurality of adjacently spaced movable hydraulic support members 30 which are moved in the direction of the arrow as the mining advances. Roof supporting members 30 are spaced approximately 3 feet to 5 feet apart.
- the cross-hatched area of trona panel 11, therefore, is the mined area the roof of which has spontaneously and progressively collapsed as roof supporting members 30 have been moved in direction of the arrow.
- the entire trona panel 11 will be mined and the space left thereby will have been filled incrementally as a result of the progressive and spontaneous collapse of the roof.
- the positioning of the movable hydraulic support members 30 is illustrated with reference to the advancement of the miner.
- Mining which is performed in a single direction commences at entry 22 and progresses towards entry 21 the former of which (22) constitutes the intake airway while the latter (21) serves as the return airway.
- the miner advances into the trona face from the same direction each time, thus keeping the operation away from the trona face which may be subject to spalling. Further, better ventilation is provided since the miner operator is never "down-wind" of the cutter head.
- FIG. 4 is an enlarged section illustrating one type of movable roof supporting member 30. Other types such as those more fully described hereinafter are also suitable. Support member 30 of FIG. 4 has been advanced adjacent the exposed face of trona panel 11. Overlying shale 40 and underlying shale 41 are shown, between which trona panel 11 to be mined is sandwiched.
- FIGS. 2A-E Movement of hydraulic support member 30 with respect to the operation of the miner 31 is illustrated in FIGS. 2A-E.
- the width of the cut as illustrated being 10 feet
- hydraulic support member 30 Prior to cutting the short face of trona panel 11, the width of the cut as illustrated being 10 feet, hydraulic support member 30 has the upper arm 32 and lower support 33 in the extended position. Support member 30 remains in this position during the cutting step (FIGS. 2A and E).
- support member 30 is advanced and forepole 34 is extended from upper arm 32 which was lowered away from upper shale 40 and lower support 33 is retracted (FIG. 2B).
- upper arm 32 with forepole 34 extended is brought into engagement with upper shale 40 and lower support 33 is fully extended (FIG. 2C).
- upper arm 32 is again withdrawn from supporting upper shale 40 and lower support 33 is withdrawn thus allowing the member 30 to advance (FIG. 2D) into position for the next cut (FIG. 2E).
- the method of the present invention offers several advantages over both the room and pillar methods and longwall method presently being employed. All of the trona within a given area or panel is extracted and no pillars or roof supporting layers need be left behind. The need for secondary supports such as roof bolting and timbering is eliminated, and the hazards of blasting avoided. Methane gas which is generally released in large volumes upon the collapse of a large roof area as in room and pillar mining is released slowly using this method, as incremental caving is employed. Because the trona face being mined is not as long as faces presently mined using the longwall technique, less support problems are presented and the hazard of overburdening the support members is better avoided.
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Remote Sensing (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
Abstract
Description
Na.sub.2 CO.sub.3 ·NaHCO.sub.3 ·2H.sub.2 O
Claims (11)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/080,271 US4268088A (en) | 1979-10-01 | 1979-10-01 | Shortwall mining of trona |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/080,271 US4268088A (en) | 1979-10-01 | 1979-10-01 | Shortwall mining of trona |
Publications (1)
Publication Number | Publication Date |
---|---|
US4268088A true US4268088A (en) | 1981-05-19 |
Family
ID=22156307
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/080,271 Expired - Lifetime US4268088A (en) | 1979-10-01 | 1979-10-01 | Shortwall mining of trona |
Country Status (1)
Country | Link |
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US (1) | US4268088A (en) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4799738A (en) * | 1981-11-03 | 1989-01-24 | Tatabanyai Szenbanyak | Mining method for working large-scale mineral deposits by the caving system |
EP0795680A1 (en) * | 1996-03-11 | 1997-09-17 | Council of Scientific and Industrial Research | Shortwall mining equipment for extraction of pillars in underground coal mines |
CN100529328C (en) * | 2005-10-08 | 2009-08-19 | 苏国民 | Mining producing method for synchronous excavation and mining drift multiplying |
CN102748026A (en) * | 2012-05-22 | 2012-10-24 | 山东科技大学 | Short-wall-box-type coal mining method |
US8770667B1 (en) * | 2013-03-14 | 2014-07-08 | Seneca Industries Inc. | Mining methods and equipment |
CN104088642A (en) * | 2014-06-30 | 2014-10-08 | 山东科技大学 | Super-short-wall coal mining method |
US9327233B2 (en) | 2010-09-14 | 2016-05-03 | Tronox Alkali Wyoming Corporation | Method of beneficiating and drying trona ore useful for flue gas desulfurization |
CN107237635A (en) * | 2017-07-06 | 2017-10-10 | 中国煤炭科工集团太原研究院有限公司 | A kind of thick solid potassium salt ore deposit recovery method of the spy for once adopting full thickness |
US10012080B2 (en) * | 2013-12-18 | 2018-07-03 | China University Of Mining And Technology | Skip-mining type wangeviry stope branch roadway filling and coal mining method |
CN110630268A (en) * | 2019-11-01 | 2019-12-31 | 西安科技大学 | Method for determining advancing direction offset of upper and lower co-mining working faces of double coal seams |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3778108A (en) * | 1972-02-29 | 1973-12-11 | Allied Chem | Trona mining method |
US4030752A (en) * | 1976-03-08 | 1977-06-21 | Atlantic Richfield Company | Longwall mining of thick underground mineral seams |
US4127303A (en) * | 1976-08-31 | 1978-11-28 | Taiheiyo Engineering Incorporated | Coal mining method at a long-walled pit face of the coal mine |
-
1979
- 1979-10-01 US US06/080,271 patent/US4268088A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3778108A (en) * | 1972-02-29 | 1973-12-11 | Allied Chem | Trona mining method |
US4030752A (en) * | 1976-03-08 | 1977-06-21 | Atlantic Richfield Company | Longwall mining of thick underground mineral seams |
US4127303A (en) * | 1976-08-31 | 1978-11-28 | Taiheiyo Engineering Incorporated | Coal mining method at a long-walled pit face of the coal mine |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4799738A (en) * | 1981-11-03 | 1989-01-24 | Tatabanyai Szenbanyak | Mining method for working large-scale mineral deposits by the caving system |
EP0795680A1 (en) * | 1996-03-11 | 1997-09-17 | Council of Scientific and Industrial Research | Shortwall mining equipment for extraction of pillars in underground coal mines |
US5769504A (en) * | 1996-03-11 | 1998-06-23 | Council Of Scientific & Industrial Research | Equipment for shortwall mining useful for extraction of pillars in underground coal mines |
CN100529328C (en) * | 2005-10-08 | 2009-08-19 | 苏国民 | Mining producing method for synchronous excavation and mining drift multiplying |
US9327233B2 (en) | 2010-09-14 | 2016-05-03 | Tronox Alkali Wyoming Corporation | Method of beneficiating and drying trona ore useful for flue gas desulfurization |
CN102748026B (en) * | 2012-05-22 | 2015-02-11 | 山东科技大学 | Short-wall-box-type coal mining method |
CN102748026A (en) * | 2012-05-22 | 2012-10-24 | 山东科技大学 | Short-wall-box-type coal mining method |
US8985700B2 (en) | 2013-03-14 | 2015-03-24 | Seneca Industries Inc. | Mining systems with guidance systems |
US8985699B2 (en) | 2013-03-14 | 2015-03-24 | Seneca Industries Inc. | Mining methods and equipment |
US9010870B2 (en) | 2013-03-14 | 2015-04-21 | Seneca Industries Inc. | Mining systems |
US8770667B1 (en) * | 2013-03-14 | 2014-07-08 | Seneca Industries Inc. | Mining methods and equipment |
US9617852B2 (en) | 2013-03-14 | 2017-04-11 | Seneca Industries Inc. | Mining systems |
US10012080B2 (en) * | 2013-12-18 | 2018-07-03 | China University Of Mining And Technology | Skip-mining type wangeviry stope branch roadway filling and coal mining method |
CN104088642A (en) * | 2014-06-30 | 2014-10-08 | 山东科技大学 | Super-short-wall coal mining method |
CN104088642B (en) * | 2014-06-30 | 2016-06-08 | 山东科技大学 | A kind of super Shortwall mining method |
CN107237635A (en) * | 2017-07-06 | 2017-10-10 | 中国煤炭科工集团太原研究院有限公司 | A kind of thick solid potassium salt ore deposit recovery method of the spy for once adopting full thickness |
CN110630268A (en) * | 2019-11-01 | 2019-12-31 | 西安科技大学 | Method for determining advancing direction offset of upper and lower co-mining working faces of double coal seams |
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AS | Assignment |
Owner name: TEXASGULF, INC., HIGH RIDGE PARK, STAMFORD, CT 0 Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:PRICE HERBERT S.;HUNTER GLEN E.;SMITH DAVID D.;REEL/FRAME:003827/0080;SIGNING DATES FROM 19790924 TO 19801218 |
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Owner name: TEXASGULF INC. Free format text: CHANGE OF NAME;ASSIGNOR:TEXAS GULF SULPHUR COMPANY;REEL/FRAME:004019/0926 Effective date: 19820415 Owner name: TEXASGULF INC., A CORP. OF TX Free format text: MERGER;ASSIGNOR:E A DEVELOPMENT, INC.;REEL/FRAME:004019/0947 Effective date: 19820226 Owner name: E A DEVELOPMENT, INC. Free format text: MERGER;ASSIGNOR:TEXASGULF INC. (MERGED INTO);REEL/FRAME:004019/0954 Effective date: 19820226 Owner name: E A DEVELOPMENT, INC., UNITED STATES Free format text: MERGER;ASSIGNOR:TEXASGULF INC. (MERGED INTO);REEL/FRAME:004019/0954 Effective date: 19820226 |